/*  $NetBSD: ip6.h,v 1.23 2007/12/25 18:33:46 perry Exp $   */
/*  $KAME: ip6.h,v 1.45 2003/06/05 04:46:38 keiichi Exp $   */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (c) 1982, 1986, 1993
 *  The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *  @(#)ip.h    8.1 (Berkeley) 6/10/93
 */

#ifndef _NETINET_IP6_H_
#define _NETINET_IP6_H_

#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */

/*
 * Definition for internet protocol version 6.
 * RFC 2460
 */

struct ip6_hdr {
    union {
        struct ip6_hdrctl {
            u_int32_t ip6_un1_flow; /* 20 bits of flow-ID */
            u_int16_t ip6_un1_plen; /* payload length */
            u_int8_t  ip6_un1_nxt;  /* next header */
            u_int8_t  ip6_un1_hlim; /* hop limit */
        } ip6_un1;
        u_int8_t ip6_un2_vfc;   /* 4 bits version, top 4 bits class */
    } ip6_ctlun;
    struct in6_addr ip6_src;    /* source address */
    struct in6_addr ip6_dst;    /* destination address */
} __packed;

#define ip6_vfc     ip6_ctlun.ip6_un2_vfc
#define ip6_flow    ip6_ctlun.ip6_un1.ip6_un1_flow
#define ip6_plen    ip6_ctlun.ip6_un1.ip6_un1_plen
#define ip6_nxt     ip6_ctlun.ip6_un1.ip6_un1_nxt
#define ip6_hlim    ip6_ctlun.ip6_un1.ip6_un1_hlim
#define ip6_hops    ip6_ctlun.ip6_un1.ip6_un1_hlim

#define IPV6_VERSION        0x60
#define IPV6_VERSION_MASK   0xf0

#if BYTE_ORDER == BIG_ENDIAN
#define IPV6_FLOWINFO_MASK  0x0fffffff  /* flow info (28 bits) */
#define IPV6_FLOWLABEL_MASK 0x000fffff  /* flow label (20 bits) */
#else
#if BYTE_ORDER == LITTLE_ENDIAN
#define IPV6_FLOWINFO_MASK  0xffffff0f  /* flow info (28 bits) */
#define IPV6_FLOWLABEL_MASK 0xffff0f00  /* flow label (20 bits) */
#endif /* LITTLE_ENDIAN */
#endif
/* ECN bits proposed by Sally Floyd */
#define IP6TOS_CE       0x01    /* congestion experienced */
#define IP6TOS_ECT      0x02    /* ECN-capable transport */

#ifdef _KERNEL
/*
 * for IPv6 pseudo header checksum
 * XXX nonstandard
 */
struct ip6_hdr_pseudo {
    struct in6_addr ip6ph_src;
    struct in6_addr ip6ph_dst;
    u_int32_t   ip6ph_len;
    u_int8_t    ip6ph_zero[3];
    u_int8_t    ip6ph_nxt;
} __packed;
#endif

/*
 * Extension Headers
 */

struct  ip6_ext {
    u_int8_t ip6e_nxt;
    u_int8_t ip6e_len;
} __packed;

/* Hop-by-Hop options header */
/* XXX should we pad it to force alignment on an 8-byte boundary? */
struct ip6_hbh {
    u_int8_t ip6h_nxt;  /* next header */
    u_int8_t ip6h_len;  /* length in units of 8 octets */
    /* followed by options */
} __packed;

/* Destination options header */
/* XXX should we pad it to force alignment on an 8-byte boundary? */
struct ip6_dest {
    u_int8_t ip6d_nxt;  /* next header */
    u_int8_t ip6d_len;  /* length in units of 8 octets */
    /* followed by options */
} __packed;

/* Option types and related macros */
#define IP6OPT_PAD1     0x00    /* 00 0 00000 */
#define IP6OPT_PADN     0x01    /* 00 0 00001 */
#define IP6OPT_JUMBO        0xC2    /* 11 0 00010 = 194 */
#define IP6OPT_NSAP_ADDR    0xC3    /* 11 0 00011 */
#define IP6OPT_TUNNEL_LIMIT 0x04    /* 00 0 00100 */
#define IP6OPT_RTALERT      0x05    /* 00 0 00101 (KAME definition) */
#define IP6OPT_ROUTER_ALERT 0x05    /* (RFC3542 def, recommended) */

#define IP6OPT_RTALERT_LEN  4
#define IP6OPT_RTALERT_MLD  0   /* Datagram contains an MLD message */
#define IP6OPT_RTALERT_RSVP 1   /* Datagram contains an RSVP message */
#define IP6OPT_RTALERT_ACTNET   2   /* contains an Active Networks msg */
#define IP6OPT_MINLEN       2

#define IP6OPT_TYPE(o)      ((o) & 0xC0)
#define IP6OPT_TYPE_SKIP    0x00
#define IP6OPT_TYPE_DISCARD 0x40
#define IP6OPT_TYPE_FORCEICMP   0x80
#define IP6OPT_TYPE_ICMP    0xC0

#define IP6OPT_MUTABLE      0x20

/* IPv6 options: common part */
struct ip6_opt {
    u_int8_t ip6o_type;
    u_int8_t ip6o_len;
} __packed;

/* Jumbo Payload Option */
struct ip6_opt_jumbo {
    u_int8_t ip6oj_type;
    u_int8_t ip6oj_len;
    u_int8_t ip6oj_jumbo_len[4];
} __packed;
#define IP6OPT_JUMBO_LEN 6

/* NSAP Address Option */
struct ip6_opt_nsap {
    u_int8_t ip6on_type;
    u_int8_t ip6on_len;
    u_int8_t ip6on_src_nsap_len;
    u_int8_t ip6on_dst_nsap_len;
    /* followed by source NSAP */
    /* followed by destination NSAP */
} __packed;

/* Tunnel Limit Option */
struct ip6_opt_tunnel {
    u_int8_t ip6ot_type;
    u_int8_t ip6ot_len;
    u_int8_t ip6ot_encap_limit;
} __packed;

/* Router Alert Option */
struct ip6_opt_router {
    u_int8_t ip6or_type;
    u_int8_t ip6or_len;
    u_int8_t ip6or_value[2];
} __packed;
/* Router alert values (in network byte order) */
#if BYTE_ORDER == BIG_ENDIAN
#define IP6_ALERT_MLD   0x0000
#define IP6_ALERT_RSVP  0x0001
#define IP6_ALERT_AN    0x0002
#else
#if BYTE_ORDER == LITTLE_ENDIAN
#define IP6_ALERT_MLD   0x0000
#define IP6_ALERT_RSVP  0x0100
#define IP6_ALERT_AN    0x0200
#endif /* LITTLE_ENDIAN */
#endif

/* Routing header */
struct ip6_rthdr {
    u_int8_t  ip6r_nxt; /* next header */
    u_int8_t  ip6r_len; /* length in units of 8 octets */
    u_int8_t  ip6r_type;    /* routing type */
    u_int8_t  ip6r_segleft; /* segments left */
    /* followed by routing type specific data */
} __packed;

/* Type 0 Routing header */
struct ip6_rthdr0 {
    u_int8_t  ip6r0_nxt;        /* next header */
    u_int8_t  ip6r0_len;        /* length in units of 8 octets */
    u_int8_t  ip6r0_type;       /* always zero */
    u_int8_t  ip6r0_segleft;    /* segments left */
    u_int32_t ip6r0_reserved;   /* reserved field */
} __packed;

/* Fragment header */
struct ip6_frag {
    u_int8_t  ip6f_nxt;     /* next header */
    u_int8_t  ip6f_reserved;    /* reserved field */
    u_int16_t ip6f_offlg;       /* offset, reserved, and flag */
    u_int32_t ip6f_ident;       /* identification */
} __packed;

#if BYTE_ORDER == BIG_ENDIAN
#define IP6F_OFF_MASK       0xfff8  /* mask out offset from _offlg */
#define IP6F_RESERVED_MASK  0x0006  /* reserved bits in ip6f_offlg */
#define IP6F_MORE_FRAG      0x0001  /* more-fragments flag */
#else /* BYTE_ORDER == LITTLE_ENDIAN */
#define IP6F_OFF_MASK       0xf8ff  /* mask out offset from _offlg */
#define IP6F_RESERVED_MASK  0x0600  /* reserved bits in ip6f_offlg */
#define IP6F_MORE_FRAG      0x0100  /* more-fragments flag */
#endif /* BYTE_ORDER == LITTLE_ENDIAN */

/*
 * Internet implementation parameters.
 */
#define IPV6_MAXHLIM    255 /* maximum hoplimit */
#define IPV6_DEFHLIM    64  /* default hlim */
#define IPV6_FRAGTTL    120 /* ttl for fragment packets, in slowtimo tick */
#define IPV6_HLIMDEC    1   /* subtracted when forwarding */

#define IPV6_MMTU   1280    /* minimal MTU and reassembly. 1024 + 256 */
#define IPV6_MAXPACKET  65535   /* ip6 max packet size without Jumbo payload*/

#ifdef _KERNEL
/*
 * IP6_EXTHDR_GET ensures that intermediate protocol header (from "off" to
 * "len") is located in single mbuf, on contiguous memory region.
 * The pointer to the region will be returned to pointer variable "val",
 * with type "typ".
 * IP6_EXTHDR_GET0 does the same, except that it aligns the structure at the
 * very top of mbuf.  GET0 is likely to make memory copy than GET.
 *
 * XXX we're now testing this, needs m_pulldown()
 */
#define IP6_EXTHDR_GET(val, typ, m, off, len) \
do {                                    \
    struct mbuf *_t;                        \
    int _tmp;                           \
    if ((m)->m_len >= (off) + (len))                \
        (val) = (typ)(mtod((m), char *) + (off));       \
    else {                              \
        _t = m_pulldown((m), (off), (len), &_tmp);      \
        if (_t) {                       \
            if (_t->m_len < _tmp + (len))           \
                panic("m_pulldown malfunction");    \
            (val) = (typ)(mtod(_t, char *) + _tmp); \
        } else {                        \
            (val) = (typ)NULL;              \
            (m) = NULL;                 \
        }                           \
    }                               \
} while (/*CONSTCOND*/ 0)

#define IP6_EXTHDR_GET0(val, typ, m, off, len) \
do {                                    \
    struct mbuf *_t;                        \
    if ((off) == 0 && (m)->m_len >= len)                \
        (val) = (typ)mtod((m), void *);         \
    else {                              \
        _t = m_pulldown((m), (off), (len), NULL);       \
        if (_t) {                       \
            if (_t->m_len < (len))              \
                panic("m_pulldown malfunction");    \
            (val) = (typ)mtod(_t, void *);          \
        } else {                        \
            (val) = (typ)NULL;              \
            (m) = NULL;                 \
        }                           \
    }                               \
} while (/*CONSTCOND*/ 0)
#endif /*_KERNEL*/

#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */

#endif /* !_NETINET_IP6_H_ */
